Marker cones have long been used as a substitute for paint-marked lanes in the temporary direction of traffic and for delineating areas with pedestrian traffic, such as crosswalks. Traffic cones are typically low-cost, brightly-colored, hollow, light-weight, stackable markers made of an elastomeric material so as to minimize damage to vehicles and the markers, themselves, when vehicles inadvertently collide with them. Their conical shape, with a base larger than the top of the cone, provides stability and helps prevent the cone from being knocked over by wind, traffic, or other causes.
To enhance visibility of marker cones, especially at night, numerous attempts have been made to equip the cones with various illumination devices. For example, various types of lights have been mounted onto the tops of the safety cones, with power sources either on top of the cones adjacent the light or with the power source positioned below the light inside the cone, with an electrical line connecting the light to the power source. One example of such an illuminated cone is described in copending U.S. patent application Ser. No. 12/423,871, filed by Lewis A. Nielson in April, 2009, which is incorporated herein by reference in its entirety. Illuminated bases have also been proposed for use with traffic safety cones.
Some of the disadvantages of existing lighted cones include:                limited angles of visibility;        a pre-set light intensity that isn't variable depending on ambient light conditions, such as bright sunshine, overcast daylight, and darkness;        constant illumination or invariable flash rates;        a water-proof seal to protect electronics from moisture due to rain, snow, sleet, etc. as well as water splashed or sprayed onto the cone;        a relatively high center of gravity for units mounted above or adjacent the top of the cone, making the cone and light assembly prone to tipping over; and        high energy requirements for conventional light bulbs.        